


After The Mixtape

by theratheller



Series: Dean's Top 13 Zep Traxx [2]
Category: Supernatural
Genre: (off screen), Castiel and Dean Winchester in Love, Dean's Top 13 Zepp Traxx Mixtape, DeanCas - Freeform, Destiel - Freeform, Domestic Fluff, Domesticity in the Men of Letters Bunker (Supernatural), Epilogue, Episode: s12e19 The Future, F/M, Fluff, Implied Sexual Content, M/M, Men of Letters Bunker (Supernatural), Third Wheel Sam Winchester, and theyre insufferable about it, castiels birthday, deans birthday
Language: English
Status: Completed
Published: 2021-03-09
Updated: 2021-03-09
Packaged: 2021-03-15 23:27:25
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,269
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29941017
Author URL: https://archiveofourown.org/users/theratheller/pseuds/theratheller
Summary: Part 2 of The Mixtape.Set after Sam found out about the mixtape Dean made Cas, and inadvertently let the cat out of the bag. The two are finally together. But that doesn't mean they're any less insufferable.In which Sam is still stuck third-wheeling, and Dean and Cas are head over heels in love.
Relationships: Castiel/Dean Winchester, Eileen Leahy/Sam Winchester
Series: Dean's Top 13 Zep Traxx [2]
Series URL: https://archiveofourown.org/series/2201943
Comments: 10
Kudos: 57





	1. The Plan

**Author's Note:**

> I hope yall enjoy this little addition to The Mixtape. I wasn't planning on doing this but it came out of nowhere.
> 
> ch1 is more of a setup while ch2 is the heart of it <3

“Sam, could I talk to you for a moment?”

Sam looked up from his laptop at Castiel. He hadn’t heard the angel approach. Cas stood awkwardly in the doorway, fidgeting slightly. His eyes were scanning either side of the hallway as if he were looking out for someone.

Sam swiftly shifted off his bed and stood, concern was framing his features.

“Is everything okay Cas?”

“Can I come in?” Cas hastily asked, not seeming to pay any mind to the other man’s question. His focus was clearly still on the hallway.

“Uh sure,” Sam replied, sounding not at all sure.

Cas shuffled in quickly, closing the door behind him. He seemed to finally relax the slightest once he was inside and out of the apparently ominous hallway.

“Seriously man, what’s wrong?” Sam tried again, his rate of concern rising by the second.

Cas’ behaviour was odd, yes. But it was more so the fact that he was seeking out Sam alone which was particularly out of the norm. Usually, this would suggest there was something wrong with Dean, or there was something Dean couldn’t know about. Either way, Sam couldn’t prophesize this being anything good.

Anxiety simmered in his chest.

“Nothing’s wrong” Castiel responded, now completely at ease while Sam panicked. “I need your help with something.”

Sam raised his brows slightly, gesturing for Cas to elaborate.

“I have an idea for Dean’s birthday.” His eyes grew as he spoke, happiness bubbling behind the blue.

Sam huffed out a sigh of relief and looked up incredulously at the ceiling of his room. Of course. He should’ve known it would be something like this. For two people who’d been completely oblivious of their feelings for each other over the years, ever since it had all come out they’d been insufferably That Couple.

Sure, their affection for each other was at times kind of adorable, but it very often became a lot. Only a few weeks prior Sam had to have a word with Dean about not mentally scarring Jack with all the PDA and innuendos. That had only helped things slightly.

“We’re already doing the whole surprise party thing, which I’m still not sure is his thing if I’m being honest.” Sam sat down at his desk as he spoke.

“Jack really wants to throw one, and Dean will play along if he must.”

“Okay sure, but what else did you wanna do?” Sam questioned with another sigh, it was late and he hoped this wasn’t going to be anything too elaborate.

“Well, I have to get him a present, especially now that we’re coupled.” Cas seemed exasperated at Sam’s slowness to catch up.

Sam held back a snort and pressed his lips together to keep from laughing at the phrasing. “Okay, so what were you thinking then?”

“Well I asked Dean what he wanted for his birthday and that promptly turned sexua-“

Sam interrupted hastily with a groan. “Cas, come on man I don’t wanna hear about that.” He shook his head before his face suddenly went blank in horror. “Oh god, you’re not here to ask me for advice on that are you because-“

Cas rolled his eyes. “No, Sam that’s not why I’m here. I need your help. I want to make him a mixtape.” His voice became hesitant at the last phrase, his eyes flickered downward.

Sam looked at him in surprise for a brief moment, before smiling lightly.

“Like the one he made you?” He asked with a quirked brow.

“Yes. Exactly.” Castiel sighed before continuing. 

“I looked up how to do it, and I snuck away everything I needed for it from Dean but-“ He pinched his face in frustration. “I don’t know what to put on it. The songs Dean chose- they- they said so much, and they had meaning behind them. Your parents- and-“

Sam interrupted Castiel’s anxious ramblings. “Woah Cas, calm down, you’re gonna be fine.”

Cas looked at him glumly. He’d clearly been stressing about this for a while.

“What ideas do you have so far?” Sam asked.

Cas glanced around, stalling for a second before reaching into his trench coat pocket and pulling out a sheet of paper. Sam reached out and hesitantly took it from him, straightening his face in preparation for whatever would be on there.

He was glad he’d done that.

“Oh wow. Um- wow.”

“They’re terrible, I knew it-“

“No, no, Cas. They’re uh- they’re very you. And they’re definitely uh- sweet?” Sam looked up at him from the list of songs, his brows raised slightly in concern.

“Don’t lie to me Sam.” Cas dejectedly sat down on the bed.

“Seriously Cas, they aren’t-“ He held back a chuckle. Laughing right now definitely would make this worse. “They’re not bad.”

Cas stared up at him blankly.

“Listen, Cas.” Sam sat down next to him. “If these are the songs that describe how you feel about Dean, then that’s what matters. He’ll love it- he’ll love it because it’s from you.”

The angel eyed him warily.

“Also don’t tell him I told you this, but he definitely secretly listens to most of these already.”

“Really?” That seemed to have been the right thing to say. Cas' tone sounded a lot more hopeful than it had a moment ago, much to Sam’s relief.

“Really. Don’t overthink it okay? He’s gonna love it.”

.

Sam was experiencing a moment of déjà vu. It looked like he wasn’t done being involuntarily dragged into his brother and his brother’s boyfriend’s schemes.

Who knew these two would somehow be more insufferable once they resolved their issues? Sam wondered if this was karma for making fun of the mixtape and inadvertently forcing them to admit their feelings for each other.

“Hey, you got a minute?” Dean stood in his doorway, the night after Sam’s conversation with Cas. He was occasionally leaning back to peer out at either side of the hallway. Sam considered telling him to go away.

Instead, he sighed and responded, putting the book he’d been reading aside.

“Come in.”

Dean wandered in, closing the door behind him.

“So. It’s my birthday soon.” He stated once inside. Sam wasn’t sure where he was going with this, but he wondered anxiously if Dean had found out about the surprise party. 

“Oh? Oh yeah it is, isn’t it?” He feigned casualness.

Dean nodded. “So that’s got me thinking. Cas doesn’t have a birthday, does he? That hardly seems fair. So I was thinking yah know- uh what if we-“ He rubbed the back of his neck awkwardly. If Sam hadn’t feared being throttled by his brother, he would’ve said Dean seemed shy when talking about Cas.

“I was thinking, what if we threw a surprise party for him?” Dean suggested hesitantly, not making eye contact as he spoke.

Sam cursed internally. The one surprise party was already enough work, he wasn’t sure he and Jack could plan two simultaneously without Dean or Cas finding out.

“Uh- I don’t know Dean. What day would we even hold it?” Sam attempted an even and dismissive tone.

“We could pick a random day, or hell we could even share birthdays, he can have mine.” 

Sam attempted to think quickly. Jack was going to be very upset with him if he screwed up Dean’s surprise party. Even more so, he shuddered at the idea of how pissed loved-up-constantly-doting-on-Dean Cas would be if Sam spoiled the surprise.

“I guess he probably should have a birthday of his own, but-“

“Done! We-“

“Wait, no Dean- I was gonna say- Shouldn’t he get to pick when it is? Maybe there’s a day he’d prefer?” Sam internally patted himself on the back for that one.

“But then we wouldn’t be able to surprise him.” Dean huffed.

Sam sighed up at the ceiling. He just wanted to get back to his book.

“How about-“ he contemplated for a moment. “Okay, what if on your birthday you get him a gift too, and that can be a jumping-off point. Right? So he still gets a surprise, but then he can actually pick when he wants his birthday to be?” Sam raised his brows. He once again felt a little smug, he was full of good ideas today.

Dean considered it for a moment, before slowly responding.

“I guess that ain’t too bad of an idea.”

“It’s a great idea.”

Dean gave him an annoyed glance before his face lit up as something suddenly hit him. “Wait does this mean you already know what he’s getting me for my birthday?”

“No.” Sam responded too quickly.

Dean grinned expectantly.

“Dean I’m not telling you. I’ve helped you, can I get back to my book now?”

His brother rolled his eyes dramatically at him and began to sluggishly walk out of the room. “Fine. Whatever.”

Sam waited for him to leave, but Dean was taking his time. He shot him one final hopeful glance as he reached the door, only to be met with a glare. With that, he finally exited the room and Sam sighed.

He really hoped everything would run smoothly from thereon. 

. 

It was a disaster. 

Sam and Jack stood in the kitchen looking down at the birthday pie - or what had once been the birthday pie and was now a pile of filling and crust splattered on the floor. Jack looked like he was going to cry and that was the last thing they needed right now. 

The day’s preparations hadn’t gone the greatest, to say the least. The only thing which had gone smoothly all day had been Claire getting Dean out of the house. He had almost burst into tears on the spot when she’d called and asked for a ‘father-daughter day’, though he wouldn’t admit it. Sam did now owe her for quote ‘dragging her into that cheesy shit’, but if he didn’t know any better he’d say she was just as happy about it as Dean was. After that though, one thing after another had gone wrong, and this was the icing on the cake- pie- whatever. 

“How are the prep-” Cas suddenly cut himself off and halted his steps. He stared down at the mess on the floor incredulously, before glancing up at Sam with an accusatory squint. 

“Sam…” 

“It wasn’t me! I-” At that Jack frowned over at him, slight annoyance, but mostly sympathy behind his widened sad eyes. 

“Okay, it was me. But it was an accident I- I’m-” 

“He’s clumsy.” Eileen cut in from where she was leaning against the counter, shaking her head at the once pie, attempting to hold back a grin. 

“This is a disaster,” Jack muttered sadly, his head falling. 

“No- no it’s not Jack. Don’t worry.” Cas walked up to Jack, avoiding the pastry on the floor. “I’ll go find another pie immediately. You guys continue the preparations- Sam- clean this up.” Cas squinted at Sam one last time and patted Jack's shoulder before storming off. 

He was back an hour later, pie in hand. 

“It was hard to find something this late, they only had pecan, but it will have to do.” He placed the pie gently on the counter, before looking over at Sam. “You aren’t allowed near this. I’m sorry.” 

Sam pressed his lips together in irritation but decided against arguing. He was probably right. He couldn’t even be mad at Cas ordering him about; he was very protective of Dean and that seemed to mean protective of Dean’s birthday too. 

“How’s everything?” Cas questioned as he looked at the now clean floor where the previous pie had been massacred. 

“It’s all good to go. The decorations are done. Food’s ready. Everyone should be here in half an hour. Dean won’t be back for another hour. We’re right on schedule.” Sam replied, sighing as he leaned against the counter. It had been a tiring day. 

“Good, good.” Cas stood in place but he glanced around anxiously. 

“Don’t worry Cas, he’s gonna love it.” 

At that Cas breathed in deeply, trying to relax. He smiled up at Sam thankfully. The poor guy had been freaking out all week in the lead up to the big day. That had only made him feel more guilty about the pie incident, Cas really didn't need more to be worried about. 

At that thought, suddenly Sam recalled something. 

“By the way, how did the mixtape end up going?” He was curious. Neither Cas nor Dean had bothered him again with their birthday plans, and while he’d been thankful at first, his curiosity was getting the better of him. 

Cas’ face lit up immediately. 

“It’s done. I worked quite hard on it, and I- Well I hope you were right and that he does like it.” His voice wavered at the end, sounding uncertain. But still, there was a small smile on his face.

“Of course he will Cas. It’s you, he’ll love it no matter what.” Sam smiled back at him encouragingly. 

As he stood there he wondered what Dean's plan was for Cas' not-birthday.


	2. The Party

**Summary for the Chapter:**

> Dean's party ends up being the cause for a lot more celebration than expected. 
> 
> Sam continues to be the teasing little brother.

Dean wandered up to the door to the bunker’s entrance. 

He couldn’t say he wasn’t suspicious. While he really had appreciated the day out with Claire, it wasn’t the most subtle of plans. Getting him out of the house on his birthday, everyone insisting that they couldn’t come, but not having any concrete reason why. 

Also, Jack had been grinning at him conspiratorially all morning. It was borderline creepy. 

He was just hoping whatever this was going to be wasn’t too elaborate. And that he’d have the opportunity to carry out his own plan for the night. He smiled to himself and took in a deep breath, reassuring himself. It was gonna be okay. 

He looked over at Claire who, he had to admit, was doing a great job at acting casual. 

“Why are you hovering, go in.” She muttered, frowning at him. 

“Yeah yeah, stop being snippy. Just because I won at mini-golf.”

“Oh, that’s so sad.” She looked at him with wide eyes. 

He frowned back at her, unsure of what she meant. 

“You’re becoming so confused and forgetful in your old age.” She snapped sarcastically. “I won. Now get inside.” She gestured at the door. 

He rolled his eyes, grinning to himself when he turned away from her. He opened the door and stepped forward. The lights seemed to be all off inside. 

As he strode towards the stairs leading down to the common area, the bunker lit up. 

“SURPRISE!” Yelled out a chorus of his friends and family. His eyes took a moment to adjust to the light before he noticed it all. 

The bunker was draped in colourful streamers of every colour of the rainbow. The table was covered in food. Balloons in the same colours as the streamers were scattered over the floor. Above it all hung a very homemade-looking crayon addled ‘Happy Birthday’ banner, he assumed he had Jack to thank for that one. 

He looked down at the crowd. Jody and the girls, Donna, Garth, several of their hunter friends, their family. All together. 

He couldn’t wipe the cheesy smile off his face no matter how hard he tried. He made his way down the rest of the steps. 

From the crowd, Jack swept forward, running up to him. 

“Do you like it!? Oh- Sorry- Happy Birthday!” He was beaming. 

Dean ruffled the kid's hair, earning him a chuckle. “I love it Jack.” 

.

As the night went on he made his way through the room, talking to everyone, accepting their birthday wishes. He ate, he drank, he ate some more. The birthday pie was the highlight of the latter activity. When he told Sam as much he had a confusingly guilty-seeming reaction in response. Who knew what that was about. 

Eventually, he had a moment alone with Cas who took the opportunity to briskly drag him away from the crowd. He led them both into the kitchen. 

“Cas you horn-” 

“Dean.” Cas glared blankly at him. 

“What? Come on, it’s my birthday! You can’t blame a man for assuming.” Dean huffed back, humour underlying his tone. Cas rolled his eyes in response, however, he couldn’t keep the small smile off his face. 

“I’m not trying to have sex with you while our entire family is only metres away.” Cas stepped up to him. “I wanted to give you your birthday gift.”

“I thought you said you weren’t trying to have sex with me.” Dean looked at him in feigned confusion. He received an eye roll in return. 

“Very funny,” Cas muttered, smiling to himself again as he shook his head fondly. Finally, he reached out for one of Dean’s hands. 

Dean smiled too, looking down at them. 

Sometimes he still couldn’t believe he got to have this. Any of it, he noted as he thought about the party and the people in the other room. But Cas especially. That had always seemed so out of reach. 

When he looked up again he saw Cas pulling a small rectangular gift-wrapped object out of his trenchcoat. He slowly lifted it up to Dean. He looked nervous. 

Dean reached for it, letting go of Cas’ hand to unwrap the gift. Occasionally looking up at him curiously as he did so. He discarded the silver wrapping paper on the counter next to them.

A mixtape. 

He smiled softly down at it. 

“Cas you made me a mixtape?” He looked up, his expression full of wonder. 

Cas looked back at him with furrowed brows, worry crowding his face. 

“I know it’s not much, but I-”

“Cas I- I love it.” He smiled down at the object again. He really did. He wasn’t just saying it. 

The idea of this angel- his angel- doing something as human as sitting down to make a mixtape. Learning how to do it, let alone putting it together. Thinking over what to put on there. All for him. The idea threatened to bring tears to his eyes. 

“You don’t even know what songs I put on it yet,” Cas muttered back nervously. But the worried expression had left his face, he was sporting a shy smile. 

“It’s from you. Whatever is on there- I’m gonna love it. I- I love you.”

Cas finally seemed to relax, letting his shoulders fall. “I love you too.” 

Dean stepped forward, only for Cas to suddenly speak up again, the nervous expression returning. 

“I should tell you. There are many pop songs on there.” He warned. 

Dean chuckled. “Cas, knowing your taste in music I guessed that one already. I'm guessing Lizzo makes an appearance there somewhere? And all your other favourites?” He raised a brow. 

Cas looked around sheepishly. “Perhaps.” 

Dean shook his head, laughing. God, he was so in love. He finally reached forward, placing a hand on the other man’s face. “I love you.” And with that, he leaned forward to meet his lips. Kissing him softly for a moment. 

When they parted, Cas sighed frustratedly, grumbling at Dean. 

“Hey, our family is only metres away, that’s all you’re getting for now.” Dean smirked at him. His boyfriend was not amused at the twisting of words as he looked back at him. “Come on, don’t be grumpy. I have a gift for you too.” 

At that Cas’ expression grew curious. He eyed Dean warily. “But it’s your birthday.”

“Yeah, well I realised that you don’t have a birthday, and we ought to pick one for you. Until then though, I got you a gift to make up for it.” 

“That’s a nice sentiment Dean, but I don’t really need a birthday, it's fine.” Cas smiled back at him amusedly. 

Dean huffed. “Well you deserve one. So come on. Pick a day.” 

Cas looked back at him shaking his head fondly. Eventually, he sighed. “Alright, let me think.” He squinted slightly as he stood there thinking. Finally, his expression cleared, becoming soft. He smiled up at Dean knowingly. “The 18th of September.” 

Dean frowned for a split-second before his eyes widened, his lip parted slightly. “That’s-” He cleared his throat, trying to stop his voice from breaking. “That’s the day we-” 

“The day we met,” Cas responded, the smile audible even in his voice. 

Dean tore his eyes away from the angel's face, trying to compose himself. He still had something to do. 

“Well uh- Until then. I had something for you.” He looked up at Cas again. This time he was the nervous one. He breathed in deeply. 

“I’m not great with words so I’ll uh- I’ll just um.” He reached into his jacket pocket. Grabbing onto the object in there, and clutching it tightly in his hand. It wasn’t visible as he took it out. 

Cas peered at the hand with curiosity. Looking back up at Dean in question. 

Dean breathed in again. Loosening his grip on the item. He held it between his fingers up towards Cas, as he gazed intently at him.

“Cas will you marry me?” He swallowed down the nerves threatening to overwhelm him as he held forward the ring. 

Cas took a sharp intake of breath. His oceanic eyes widened, as he looked down at the simple silver band and back up at Dean. They immediately began to water. 

They stood in silence as Cas gaped at him. 

After a minute, Dean cleared his throat. “Would really love it if you’d answer buddy.” 

That seemed to snap Cas out of his trance. He blinked rapidly. Before smiling up at Dean, he was practically beaming. 

“I- Of course- Dean I-”

He was immediately cut off by Dean’s lips crashing against his own. Relief flooded them both. 

When they parted both of them had tears streaming down their faces, but neither seemed to care. Suddenly, Dean’s eyes widened. 

“Shit!’ 

‘Dean, what’s wrong?” Cas’ expression immediately grew grave. 

Dean looked down at the ring in his hands. And then looked up at the ceiling helplessly, wiping at his face. “I forgot- I forgot to get down on one knee.” He mumbled, groaning dramatically. 

Cas barked out a laugh. “Dean-” He chuckled again. “It’s fine.” 

Dean looked back at him with a pout. 

“Seriously. I don’t need you to get down on one knee for me.” He paused. “Can I have my ring now?” He nodded at the ring still in Dean’s hand. 

Dean huffed out a laugh, his expression brightening again. “You can have anything you want.”

. 

Sam called out hesitantly as he searched for the two missing party-goers. 

“Cas? Dean? Are you in there? I’m about to open this door so please just- Okay I’m opening the door now. You’ve been warned!” He began to slowly open the door to Dean’s room. Before he could open it all the way a voice behind him startled him. 

“What are you doing?” 

He jumped and turned around to see Cas and Dean standing there - fully clothed - to his relief. 

“I was looking for you guys! Everyone’s missing you.” He replied defensively. 

“We were in the kitchen you dumbass.” Dean huffed out a laugh. Looking over at Cas amusedly. 

“Yeah well, I’ve been living with you two love birds for months now. Can’t blame me for assuming.” 

“Fair point,” Cas replied seriously. 

Dean snorted, however, his cheeks reddened slightly, and he glanced around haphazardly at the insinuation. 

Then, he looked over at Cas, and they shared a look. Sam tilted his head curiously, Dean had suddenly seemed to grow nervous. His expression was tight. 

“Uh- so since you’re here we- we have something to tell you.” He looked up at Sam warily. 

Sam quirked a brow, looking between the two of them. Dean seemed anxious, however, Cas seemed to be beaming. So it couldn’t be anything too bad. He decided that meant it was okay to mess with Dean some more. 

“You’re not pregnant are you?” He asked Dean, with the best serious expression he could muster. 

Cas tilted his head confusedly at that. “Sam that’s not how-” 

“He’s being a dick,” Dean muttered to Cas before turning to Sam with a glare. “Stop being a dick I’m trying to tell you something.” 

Sam choked down his giggles and nodded at Dean to continue. 

“We’re uh- We-” He seemed to be having trouble getting the words out. He glanced over at Cas anxiously. 

Cas’ expression softened. He looked at Dean so adoringly it sort of made Sam’s heart melt. Finally, he looked over at Sam and spoke. 

“Dean and I. We’re engaged.” He stated softly, smiling up at him.

Sam’s mouth dropped open. “Holy shit.” He looked over at Dean wide-eyed. “That was your present! Holy shit- I- You guys-” He continued sputtering for a moment, unable to process it immediately. 

After a moment, his face broke out into a toothy grin. “I’m so happy for you guys!” 

At that, he pulled the two men in front of him into his arms. They both yelped out as he crushed them in his hug. “Sammy, I can’t breathe.” Dean yelped out dramatically.

Sam chuckled in return and gripped them tighter for a short while, before finally letting go. 

He beamed at both of them. “You guys deserve this so much.” 

Cas grinned up at him. Dean’s expression softened, his eyes seemed to water slightly as he cleared his throat. “Thanks Sammy.” 

They all stood there for a moment before Dean interrupted the silence.

“Anyway. Let’s get back to this party, I want more pie.” With that, he reached for Cas’ hand and began to lead him there. 

Sam smiled at the two of them for a moment before following.

**Notes for the Chapter:**

> I really hope yall enjoyed this. The first chapter was more of a setup, while this one was really the heart of it. xx


End file.
